For Location Service of mobile communication networks, location information of target User Equipment (UE) is obtained by location techniques, where UE demotes a user terminal to be located in mobile communication network, and location information may be either geographical latitude and longitude information or location of local streets. Location estimate of target UE obtained by LCS system may be provided to target UE for self positioning of the target UE, or provided for communication system itself, for zonal charging or operation maintenance. Location information thereof may also be provided to other client application ends requesting for location of target UE, such as organizations and individuals, for supplement service. Therefore, location service is of wide application in terms of emergency assistance, vehicle guidance, intelligent traffic system, work dispatching, team management, mobile yellow page inquiry and network performance enhancement, etc.
FIG. 1 is a simplified diagram illustrating conventional logic structure of Location Service (LCS) in mobile communication networks. As shown in FIG. 1, a network client 101 may issue a LCS request to a network system 102 for obtaining a location estimate of a network user 103. The network client may be a LCS Client comprising a software and/or hardware entity that interacts with network for the purpose of obtaining location information for one or more target network users. The network system may be a network with LCS system comprising a software and/or hardware entity offering LCS capabilities (including accepting requests, servicing requests, and sending back responses to the received requests). The network user can be a Mobile Station (MS) or Mobile Equipment (ME) or simply the target User Equipment (UE) in the mobile networks. The network client can be either external or internal to the network system or can be an alternative network user or even the network user itself. The LCS request may also issued by the network system based on system internal conditions or capabilities.
In the LCS system, function logic entities for implementing location service include Gateway Mobile Location Center (GMLC), user data storage server (HLR/HSS), Central Network (CN) and Radio Access Network (RAN). GMLC may further include Requesting GMLC (R-GMLC), Home GMLC (H-GMLC) and Visited GMLC (V-GMLC). R-GMLC is a GMLC for receiving the location information request initiated by LCS Client to target UE, H-GMLC is a GMLC which the target UE belongs to, V-GMLC is the GMLC in the network with LCS system that target UE visits, namely the GMLC that target UE is located. R-GMLC, H-GMLC and V-GMLC may be the same physical entity, or be different physical entities. CN, acting as an interface between the network and network subscriber and a traffic distributor, includes functional entities such as one or more Mobile Switching Centers (MSC) or General Packet Radio System (GPRS) nodes, e.g., Serving GPRS Support Nodes (SGSN). Through capabilities of the MSC/SGSN and/or UE itself, the target UE may be detected by the LCS system for its network connection status, idle or active, location in terms of MSC/SGSN area, authentication or subscriber profiling, privacy verification, etc.
For deferred location request, the location service response may not be immediately provided to the location service requester or LCS Client. The positioning mechanism and the location report may not be triggered until the occurrence of an indicated event (e.g., certain time or event specified by the LCS Client). However, if the target UE to be positioned is in an abnormal state, for example no signal, or being switched off etc., the MSC/SGSN may not be able to successfully send the event to the UE. Therefore the event driven deferred location request procedure usually be terminated abnormally without providing an appropriate cause for the LCS Client. Similarly, in case when a LCS Client issues a request to cancel a previously issued deferred location request, the MSC/SGSN may not be able to successfully send the event cancellation request to the UE if it is in an abnormal state. Therefore, the UE will be unable to actually cancel the deferred location request triggered by the original event. Without knowing the status of the UE, additional cancellation requests later issued by the LCS Client issues may also fail. Either case reduces the rate of success to send the event driven deferred location request or event cancellation request to the UE and eventually leads to low efficiency and poor quality for the network to provide location services to its subscribers. diminishing the utilization, reliability, and value of the current available networking technology.
From the above, it is seen that an improved technique for sending the deferred location service request or cancellation request in mobile communication network is desired.